5种鱼类标志对草鱼临界游泳速度的影响

采用被动整合雷达标志法(PIT)、切鳍标记、荧光标记、超声波标志和T型标志这5种标志方法对草鱼(Ctenopharyngodon idellus)进行标记后,测定其临界游泳速度,研究5种不同标记对草鱼游泳能力的影响。将试验草鱼按不同体长分为3组:15~18 cm,18~21 cm,21~25 cm,每个体长组均设置对照组,并分别进行以上5种鱼类标志,测量标志后草鱼的绝对临界游泳速度和相对临界游泳速度。采用SPSS17.0统计软件进行数据的分析比较。研究结果表明,随着体长增加,草鱼的绝对临界游泳速度增大,相对临界游泳速度减小;超声波标志对3个体长组草鱼的临界游泳速度均有极显著影响(P0.01),标志后草鱼绝对临界游泳速度分别下降18.72%、16.40%、23.15%,相对临界游泳速度分别下降18.95%、17.78%、21.86%;T型标志对15~18 cm体长组草鱼的临界游泳速度有极显著性影响(P0.01),标志后草鱼绝对临界游泳速度下降8.35%,相对临界游泳速度下降9.30%,对体长大于18 cm的草鱼无显著性影响;PIT标志、切鳍标记和荧光标记对这3个体长组草鱼的临界游泳速度均无显著性影响(P0.05)。

Effect of five tagging methods on critical swimming speed of grass carp, Ctenopharyngodon idellus

This research assessed the effect of five tagging methods: namely, PIT marking, fin amputation marking, fluorescent marking, ultrasound marking and T-type marking, on the critical swimming speed of grass carp Ctenopharyngodon idellus. Grass carp with a body length of 15?25 cm (standard length, SL) were divided into three size groups: short body length (15?18 cm), medium body length (18?21 cm) and long body length (21?25 cm). Critical swimming speed was measured for 144 fish in an annular flume with a water temperature of (16±1)℃. SPSS17.0 software was used for data processing. The results showed that the absolute critical swimming speed of the grass carp tended to increase, while the relative critical swimming speed tended to decrease along with an in-creasing body length. Ultrasonic tagging showed a significant impact (P<0.01) on the swimming ability of the fish in all size groups (body length 15?25 cm). The absolute critical swimming speed of the grass carp in each of the three size groups (short, medium, large) decreased by 18.72%, 16.40% and 23.15%, respectively, after ultrasound tagging, and the relative critical swimming speed of the three groups decreased by 18.95%, 17.78% and 21.86%, respectively. T-type tagging also showed a significant impact (P<0.01) on the swimming ability of grass carp in the short body length group: their absolute critical swimming speed decreased by 8.35%, whereas their relative critical swimming speed decreased by 9.30%. No significant impact of T-type tagging was detected on the critical swimming speed of grass carp with a medium or long body length (18?25 cm). Finally, no significant impact on swimming speed was detected for fish with a PIT tag, fin amputation marking or fluorescent tag.